OP, its ur lucky day! DJ Lord_Byron's here to bring you dank beatz and chillin sounds to get down to, along with factual information about what goes into such dankne$$.
First we get started with the experiental, vibey sound's of Miami with Lofty305, beat by DJ Complex. Known for his strong samples and large vocal range, Lofty is a great intro to south Florida underground.
https://soundcloud.com/lofty305/she-chose-lofty305-x-djcomplex72-haitiansilk
Now don't let the title fool you, these cats arent from Costa Rica. That's Billionaire Black and Uno, two of the 600 GD set from Chicago. You heard that right. 600. GD. They're beefing with Chief Keef's iconic 300 set, and all of them have been involved in gang violence. This can be heard in their music, and while this melodic, on-tune, vibe-fest might seem chill on the surface, it opens a window into a dark world and a dream of paradise. Produced by Ramsay Tha Great.
https://soundcloud.com/omgpurppppp/billionaire-black-x-uno-x-costa-rica
Back to Florida, it's time for Denzel Curry. The hot up and coming MC is from the same high school as Lofty305, Spaceghost Purp and a few other prominent rappers. They were also childhood friends with Trayvon Martin, and Denzel's older brother died mysteriously in police custody. Life isn't easy in Coral City, and Denzel's relentlessly defiant flows reflect that. Produced by the Dopeboyz.
https://soundcloud.com/denzelcurryph/denzel-curry-certified-prod-by-the-dope-boyz
Staying in the south, let's try jamming to some Big KRIT. The Mississippi native lays down the struggles of being an underground rapper, and comes off as more genuine and honest about the less glamorous aspects of hip-hop. He also has a unique way of building tension throughout the whole song, rather than trying to shove all the emotion in the song into your ears at once. Fortunately, KRIT just signed his first deal, and has a bright music future in front of him. He also produces most of his own beats, and has produced for many top 40 artists including Lil Wayne and Nicki Minaj.
https://soundcloud.com/bigkrit/chapter-one
"But DJ Lord_Byron, what about the west coast underground scene?"
Great question, and we can look to Nacho Picasso for a prime example of a unique talent. The Seattle native has a drug dealing past, and often raps back to his days leaning off his ass and selling coke. Luckily, the EDM duo Blue Sky Black Death have produced 2 full albums for him exclusively, meaning beat quality is never and issue for the rapper.
https://soundcloud.com/dope-music-blog/nacho-picasso-crime-waves
"But I'm tired of drugs/bitches/money songs!"
Fine here's a song about sacrificing virgins to the devil.
Its also by Captain Murphy, who is Flying Lotus.
https://soundcloud.com/captain-murphy-music/04-the-ritual-prod-just-blaze
And for all you hyphy beasts, here's some fresh 40. Rep the bay, stay loyal to the soil.
https://soundcloud.com/theworldsfreshest/e40-the-worlds-freshest-im-laced-ft-cousin-fik
Ok, that wasn't chill, but its still a danky song. I'll make it up to you right now with Issa Gold, the MC of the Underachievers. This solo track, produced by Ion, is a great example of the floaty, acid trip inspired beats and lyrics Issa is known for. He also has a phenomenal flow, and rarely recycles lines. Great to chill to.
https://soundcloud.com/issa-gold/02-musical-chairs-prod-by-ion
LA based rapper Bones is probably the most successful true underground rookie to come out in the last few years. The pale white rapper often collabs with the Florida based Raider Klan crew that includes Denzel Curry. This jam demonstrates his sp00ky beat mastery and dank rhymes.
https://soundcloud.com/teamsesh/bones-whitepunkondope?in=teamsesh/sets/bones-skinny
POUYAAAAAAA
https://soundcloud.com/pouya-kevin/suicidal-thoughts-in-the-back-of-the-cadillac-prodmikey-the-magician 
